From 559fc9746c98d876ed04d353146e1222e5f03241 Mon Sep 17 00:00:00 2001
From: Tomoki Shirasawa <tomoki.shirasawa.kk@hitachi-solutions.com>
Date: Sun, 28 Jan 2018 13:38:51 +0900
Subject: [PATCH] signal: check_signal must be called after check_need_resched.

---
 arch/x86_64/kernel/syscall.c |  4 ++--
 kernel/mem.c                 | 10 +++++-----
 kernel/syscall.c             | 10 +++++-----
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/arch/x86_64/kernel/syscall.c b/arch/x86_64/kernel/syscall.c
index ec62ba65..e11b0e92 100644
--- a/arch/x86_64/kernel/syscall.c
+++ b/arch/x86_64/kernel/syscall.c
@@ -252,8 +252,8 @@ SYSCALL_DECLARE(rt_sigreturn)
 		regs->gpr.rflags &= ~RFLAGS_TF;
 		info.si_code = TRAP_TRACE;
 		set_signal(SIGTRAP, regs, &info);
-		check_signal(0, regs, 0);
 		check_need_resched();
+		check_signal(0, regs, 0);
 	}
 
 	if(ksigsp.fpregs && xsavesize){
@@ -820,8 +820,8 @@ do_signal(unsigned long rc, void *regs0, struct thread *thread, struct sig_pendi
 			regs->gpr.rflags &= ~RFLAGS_TF;
 			info.si_code = TRAP_TRACE;
 			set_signal(SIGTRAP, regs, &info);
-			check_signal(0, regs, 0);
 			check_need_resched();
+			check_signal(0, regs, 0);
 		}
 	}
 	else {
diff --git a/kernel/mem.c b/kernel/mem.c
index 62cb2065..061b2e48 100644
--- a/kernel/mem.c
+++ b/kernel/mem.c
@@ -1212,10 +1212,6 @@ static void page_fault_handler(void *fault_addr, uint64_t reason, void *regs)
 			info._sifields._sigfault.si_addr = fault_addr;
 			set_signal(SIGSEGV, regs, &info);
 		}
-		if(interrupt_from_user(regs)){
-			cpu_enable_interrupt();
-			check_signal(0, regs, 0);
-		}
 		goto out;
 	}
 
@@ -1224,7 +1220,11 @@ static void page_fault_handler(void *fault_addr, uint64_t reason, void *regs)
 out:
 	dkprintf("%s: addr: %p, reason: %lx, regs: %p -> error: %d\n",
 			__FUNCTION__, fault_addr, reason, regs, error);
-	check_need_resched();
+	if(interrupt_from_user(regs)){
+		cpu_enable_interrupt();
+		check_need_resched();
+		check_signal(0, regs, 0);
+	}
 	set_cputime(0);
 #ifdef PROFILE_ENABLE
 	if (thread->profile)
diff --git a/kernel/syscall.c b/kernel/syscall.c
index 2d5f8ac2..dd53b4de 100644
--- a/kernel/syscall.c
+++ b/kernel/syscall.c
@@ -9429,11 +9429,6 @@ long syscall(int num, ihk_mc_user_context_t *ctx)
 
 	save_syscall_return_value(num, l);
 
-	if (!list_empty(&thread->sigpending) ||
-	    !list_empty(&thread->sigcommon->sigpending)) {
-		check_signal(l, NULL, num);
-	}
-
 #ifdef PROFILE_ENABLE
 	{
 		unsigned long ts = rdtsc();
@@ -9472,6 +9467,11 @@ long syscall(int num, ihk_mc_user_context_t *ctx)
 	}
 #endif /* POSTK_DEBUG_TEMP_FIX_60 && POSTK_DEBUG_TEMP_FIX_56 */
 
+	if (!list_empty(&thread->sigpending) ||
+	    !list_empty(&thread->sigcommon->sigpending)) {
+		check_signal(l, NULL, num);
+	}
+
 #ifdef DISABLE_SCHED_YIELD
 	if (num != __NR_sched_yield)
 #endif // DISABLE_SCHED_YIELD